The current and projected studies are aimed at uncovering the nature of T lymphocyte surface receptors and also to determine their source as well as clarify the role they play in the recognition and reaction to foreign histocompatibility and tumor antigens. The mechanisms by which immune lymphocytes mediate target cell lysis is another avenue which will be explored. In addition we intend to extend our work in immunopathology and inflammation which is aimed at eliciting the role of leukocyte granule enzymes in the progress of inflammatory diseases. Also to be considered in this regard is the role of naturally occurring inhibitors to the protease activity of these enzymes which are found in formal serum and many inflammatory exudates. Studies have also begun which will study the role of inflammatory cells and their mediators in malignant transformation of normal cells. Also studies have been initiated in an attempt to determine the role of inhibitors of inflammatory reaction which are released by malignant cells. Still another group of studies will be concerned with the role of cell mediated immunity in the progress of the tissue destructive phase of chronic inflammatory periodontal disease.